#7: [Dogfood] Repository root is missing e2e-live.txt

[penso]

Automated handoff for #7.

Issue: #7
Base branch: main
Head branch: issue-7
Commit: 9b7a988

[penso]

Summary

This branch adds a single new repository-root file, e2e-live.txt, with the contents dogfood live ok.

I did not find any in-repo code path, workflow, or test that reads this file, so there is no obvious Rust or CI regression in the branch itself. The change appears to be satisfying an external dogfood/sentinel contract.

Risks

• The repository does not validate this contract anywhere. If the external check expects different contents, encoding, casing, or a different path, this branch will still pass local review and CI while failing in the real dogfood flow.
• Because the requirement is undocumented in-tree, the file is easy to remove later as "dead weight", which would reintroduce the issue without any automated signal.

Recommended human checks

• Confirm the external dogfood check only requires a file at repository root named e2e-live.txt, and that dogfood live ok is the exact expected payload.
• Verify the check against a fresh clone or the same archive format the dogfood system consumes, not just the current working tree.
• If this file is part of a durable contract, document that contract somewhere discoverable so future cleanup does not delete it.